1. Field of the Invention
The present invention relates to an image capturing apparatus and method, and more particularly, to an image capturing apparatus and method, in which the limit of the application of blurring to an input image is determined with the use of a database of recognizable blur levels, and the input image is processed by applying filtering properties corresponding to variations in digital gain and an exposure time.
2. Description of the Related Art
Devices equipped with cameras such as digital cameras or camera phones have recently become widespread.
A typical digital camera includes a lens and an image sensor. The lens collects optical signals reflected from a subject, and the image sensor then detects the optical signals collected by the lens and converts the detected optical signals into electric image signals. Image sensors are largely classified into a camera tube and a solid-state image sensor. Examples of the solid-state image sensor include a charge-coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS).
In order to properly output an electric image signal, a sufficient amount of light must be provided to the image sensor. If an insufficient amount of light is provided to the image sensor, the quality of an image may deteriorate.
In order to secure a sufficient amount of light, an exposure time or digital gain may be increased. Specifically, the amount of light that can be provided to the image sensor may be increased by increasing the exposure time, or the amount of light that has already been incident upon the image sensor may be amplified by increasing digital gain.
However, an increase in the exposure time is highly likely to result in blurry images, and an increase in digital gain is highly likely to amplify not only the amount of incident light of a subject but also noise.
Therefore, what is needed is a way to determine an optimum exposure time and optimum digital gain, which can effectively compensate for a light shortage while preventing the deterioration of the quality of an image.